1.單表動態條件查詢
1)單字段作為參數
直接用@param設置的值作為注入就好了

@Select("select * from ppms_person_message where create_time = #{testValue}")void test(@Param("testValue") String testValue);

2）對象作為參數
注意：在@param內的值不為“ew”的時候會提示找不到條件參數

@Select("select * from ppms_person_message ${ew.customSqlSegment}")Page<PersonMessage> selectTestPage(@Param("page") Page<PersonMessage> page, @Param("ew") QueryWrapper<PersonMessage> qw);

2.多表聯合動態條件查詢
1>使用wrapper
注意：1）${ew.customSqlSegment}僅為where下的條件
2）join on后面的條件需要使用另外的param

@Select("select m.* from ppms_person_message m " +"left join ppms_notice n on n.id = m.notice_id and n.create_time = #{testValue}" +"${ew.customSqlSegment}")void test(@Param("testValue") String testValue, @Param("ew") QueryWrapper<PersonMessage> qw);

2>使用標簽
注意：1）動態條件外雙引號改為單引號，內單引號改為轉義雙引號（"）
2）使用遍歷條件時需要在最外成加上<script></script>標簽

@Select("<script>" +" ( SELECT" +" '3' AS `type`," +" COUNT(*) AS `num`," +" SUBSTR( max( publish_time ), 6, 5 ) AS `time`" +" FROM ppms_notice" +" WHERE del_flag = '0' " +" )" +" UNION" +" ( SELECT" +" '1' AS `type`," +" COUNT(*) AS `messageNum`," +" SUBSTR( max( t.create_time ), 6, 5 ) AS `time`" +" FROM" +" `ppms_person_task` t" +" WHERE" +" t.`status` = '1'" +" AND (t.receiver_id = #{dto.receiverId}" +" <if test='dto.orgId != null and dto.orgId != \"\"'>" +" or t.receiver_id = #{dto.orgId}" +" </if>" +" <if test='null != dto.roleIds and dto.roleIds.size > 0'>" +" or t.receiver_id in" +" <foreach collection='dto.roleIds' item='item' close=')' open='(' separator=','>" +" #{item}" +" </foreach>" +" </if>" +" )" +" AND t.del_flag = '0'" +" )" +" UNION" +" ( SELECT" +" '2' AS `type`," +" COUNT(*) AS `num`," +" SUBSTR( max( m.create_time ), 6, 5 ) AS `time`" +" FROM" +" ppms_person_message m" +" WHERE" +" (m.receiver_id = #{dto.receiverId}" +" <if test='dto.orgId != null and dto.orgId != \"\"'>" +" or m.receiver_id = #{dto.orgId}" +" </if>" +" <if test='null != dto.roleIds and dto.roleIds.size > 0'>" +" or m.receiver_id in" +" <foreach collection='dto.roleIds' item='item' close=')' open='(' separator=','>" +" #{item}" +" </foreach>" +" </if>" +" )" +" AND m.`status` = '0'" +" AND m.del_flag = '0'" +" )" +"</script>")List<MessageRespVo> selectUnReadNumByUserId2(@Param("dto") TaskPageDto dto);

總結

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